


A Portal Problem

by PartoftheShadowWorld



Category: The Infernal Devices Series - Cassandra Clare, The Mortal Instruments Series - Cassandra Clare
Genre: Crossover, Other, TMI/TID crossover, Time Travel
Language: English
Status: In-Progress
Published: 2017-12-06
Updated: 2017-12-06
Packaged: 2019-02-11 05:51:30
Rating: General Audiences
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 1
Words: 3,342
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/12928869
Author URL: https://archiveofourown.org/users/PartoftheShadowWorld/pseuds/PartoftheShadowWorld
Summary: What if those of TID actually got to meet their descendants from TMI??Disclaimer: I am not scientific in the least so the explanation for all this is very basic and not scientific at all.





	A Portal Problem

**Part 1**

Charlotte sat in the drawing room and looked at her watch and then to the door expectantly. She was waiting on her husband, the tea cart full of a fragrant pot and Henry’s favorite scones beside her chair. He had been spending more and more time down in his basement converted laboratory lately, barely steeling himself away long enough to sleep, never mind eating. Charlotte had been worried about him and begged him to join her for tea until he finally obliged. Just as she was about to go charging down there to pull him back up here herself Henry burst through the door in a flurry of excitement.

  
“Lottie! Lottie! I think I’ve done it! I’ve done it I tell you!” He paced excitedly around the room, too wound up to stay in one place. “Henry? What on earth do you mean?” Charlotte almost yelled at her husband to get his attention. Henry looked at her with an almost manic gleam in his eye. “Time travel Lottie, I think I’ve made it possible.”

  
“But how Henry?” she asked almost hesitant to hear the answer. “One word Lottie. Portals. I’ve been experimenting with the configuration Magnus had helped with me before and I think I’ve successfully added the element of time travel to it. So that we may choose at what time we were to arrive at our destination.” Henry declared proudly. Charlotte just looked at him in shock and slight horror. “Are you sure that isn’t dangerous Henry? Surely there are so many things that could go wrong.” She implored him to think of the possible consequences for trying to conquer such an elusive force as time itself. Henry was not listening to her though, he was too drunk on the idea of his latest, and possibly biggest yet accomplishment, simply talking over her. “Think about what this could mean Lottie!” “I am Henry. . .that’s what I’m afraid of,” she whispered in response to his proclamation.  
By the next day Henry had gathered the others of the London enclave at the institute to witness his first demonstration of his new kind of portal. Magnus, Gabriel, Cecily, Gideon, Sophie, Will, Tessa, and Charlotte were all crammed into the free space in his workshop with Henry beaming proudly in front of them. “It’s all rather simple really. . . “ he began and then dived right into an incredibly complicated explanation involving the various equations and runes needed to create a portal and what he had modified to add the element of time. “Now, when one chooses where to go they can also choose when to arrive as well,” he added to the end of his summary. Magnus’ expression shaped into one of great intrigue at the idea and all the possibilities it could bring him. Gabriel looked skeptical, Gideon fairly alarmed, and Will appeared positively giddy at the idea. “Does this mean I can now portal back in time and play trick after trick on an unsuspecting Lightworm??” Will inquired with a hardly suppressed giggle. Gabriel glared at him and Cecily simply rolled her eyes while Tessa closed hers seeming to ask silently for patience with her husband. Henry didn’t seem to notice the humorous content of Will’s question when he answered it. “Unfortunately we do need to be careful when choosing a time and pace. It must be a different place from where we were previously at that time for we cannot exist in the same place at the same time as our counterparts in the past. For example, yesterday Lottie and I were having tea here in the institute at 2:00 pm, therefore if we were to venture back to that time we must also travel to another part of the world.” Gabriel smirked at Will as if his brother-in-law’s entire plan to make him miserable throughout life had been foiled. Will looked back at him with innocent eyes and many other strategies up his sleeve.

  
“So!” Henry clapped his hands together in expectation, “Who wants to be one of the first to give it a go?” They all glanced anxiously at one another until Cecily stepped deliberately forward. “I will!” She said resolutely and then with an audible groan Gabriel stepped forward as well. Will followed suit and reached back for Tessa who still looked hesitant. “Come on Tess, we can’t let Cecy and Lightworm have all the fun,” he teased. Gabriel turned his questioning look on his brother. Gideon peered back at his wife with a grave expression. “I can’t let Gabriel go on his own my love, I must go with him but I ask that you stay behind to both keep watch and be here to alert the clave if anything should go awry,” he appealed to his wife. She came forward and placed a hand gently on his face in a loving gesture before stepping away and simply nodding her head. Charlotte heaved a heavy sigh and stepped forward at last to join the rest of the group.

  
Henry beamed proudly at all of them. “Wonderful!” He exclaimed. “Now, where would we like to go? And when shall we go there?” At this Tessa actually perked up, “I’ve actually been missing New York more than usual lately.” Henry nodded in agreement, “That destination would work perfectly. As for the time, shall we we aim simply for yesterday afternoon?” The rest of the group assented to this suggestion while Henry turned to Magnus, “Mr. Bane, if you don’t mind?” Magnus grinned at him in response and they went to work drawing the portal. When everything was ready Tessa walked to the forefront of the group to go first since she was the only one who had actually been to New York before. The portal seemed like every other one they had all seen, perfectly normal for all considerations, that is until Tessa stepped through it. As she did the magic doorway seemed to darken sinisterly before them and something seemed terribly wrong. Panicked at the idea of something happening to Tessa, Will bolted in after her, with the rest of the group following close behind him. Gideon, bringing up the end of the body, had just enough time to throw himself in before the portentous portal snapped shut with a bang. Sophie and Magnus stood side by side staring at the space where everyone had disappeared, identical looks of wide-eyed shock on their faces.

  
**Meanwhile at the New York institute in present day. . .**  
Clary and Simon had been sparring in the training room when they heard a roaring commotion sound throughout the institute. They grabbed the nearest actual weapons closest to them and dashed out into the hall down to the front door, meeting Jace, Isabelle and Alec on the way. When they all arrived they were met by a very disheveled looking group of people appearing as if they were going to a costume party in the middle of the day.

 

**Part 2**

The entryway of the New York institute was in an uproar. Alec, Jace, Izzy, Clary and Simon all poised with weapons in their hand, ready to do battle if need be. “Who are you?” Alec demanded in a threatening tone, “Why are you here?” The strange looking group in front of them almost seemed not to notice he had said anything, they had all landed in a heap on the floor and were having a hard time getting up. They appeared to be disoriented, though by what the New York shadowhunters had not a clue. 

Finally, one of the newcomers, dressed in an old fashioned suit complete with a waistcoat, lifted his dark head to scan the room around them. When his gaze landed on Clary he jumped back with a look of horror on his face. “Egads!” he yelped, “Something’s happened to Charlotte and Henry, they seemed to have combined and mutated to form that  _ thing _ in front of me!” He looked around his fellows in a panic, “What sort of hellish dimension have we tumbled into? Quickly! Check yourselves to see we are all indeed still our separate selves!” 

A small brunette woman stepped forward with an irritated look on her face. “By the Angel Will, nothing has happened to either Henry or myself. Why must you always be so dramatic?” She wore a very old fashioned dress that had something on the back. . .wait. Was that a bustle?? Alec thought wildly, vaguely recalling a night when he had been very tired from a mission and had let Magnus control the conversation, dragging on about which styles he liked best throughout the centuries. Of course, it wouldn’t have been an exchange on one of Magnus’s favorite topics - fashion - without several visual aides, and apparently Alec had absorbed more than he realized because he recognized this now. Something didn’t feel right, Alec was beginning to doubt these people were just highly dedicated cosplayers. 

The woman dusted off her jacket before moving on to a red haired man beside her who looked more a mess than any one of his companions. She peered around her party, seeming to take in their condition and once she had it her mind they were all in order she turned to Alec and his family. Though she was small, she had a very dignified air about her and a familiar undaunted expression on her face. A quote from Shakespeare’s _ A Midsummer Night’s Dream  _ came to Alec’s mind in that moment, “Though she be but little, she is fierce!” He had the impression that this woman was much more than she appeared to be, that she was a force to be reckoned with, not unlike Clary. It finally dawned on him, that’s why she seemed so familiar, she and Clary were built the exact same way, from their vertically challenged stature right down to the determined set of their jaws. 

Her demeanor said she was unafraid and somehow in control of the situation, though he could tell with a trained eye her hands were prepared to go for a weapon that must be hidden in her skirts if necessary. 

“Hello, my name is Charlotte Branwell Fairchild, consul of the nephilim,” she introduced herself formally in an English accent. “Might you be kind enough to tell us where we are?” she asked. Alec wasn’t the only one taken aback by her introduction, Jace narrowed his eyes and Izzy had let out a small gasp. “But that’s impossible,” Izzy whispered, “Consul Fairchild died decades ago. Besides, she’d be like 150 years old by now. Unless you’re a warlock or a vampire you couldn’t possibly live that long.” 

“Or you could be a zombie.” Simon added in a surprisingly less shocked tone. Izzy turned to glare at him and he shrugged back at her. “What? At this point nothing in this world would surprise me anymore.” 

One of the younger women walked resolutely to Charlotte’s side. If Charlotte looked intimidating this woman looked absolutely ferocious, ink black hair clouded around her face in ringlets that had come loose from the bun at the back of her head framed blazing blue eyes not unlike Alec’s own.

“None of you answered her question. Where are we?” She emphasized every word menacingly, glaring at each one of them in turn. Jace was the one who answered, “You’re in New York, at the institute.” “And the year?” She countered, taking in Jace’s faded ripped jeans and leather jacket. He furrowed his brow at her, “2012, of course.”  

During this exchange Charlotte, if that was her real name, had paled considerably. Her pallor at this point made the suggestion of her being a vampire even more reasonable. She glanced back at the red haired man with wide eyes. “Henry? What have we done?” she managed out in a whisper, her cool and calm demeanor appeared to crumble in front of them. Henry seemed to perk up a bit for her, “Well Lottie, I did say our main problem was that we could not exist in the same place at the same time, and we seemed to have managed to avoid that.” He gave her a weak smile that didn’t seem to help at all if her expression was any indication. 

A rustle of movement in the back of the room drew Alec’s scrutiny to a woman peering out from behind the dark haired man who had spoken in hysterics earlier. He immediately recognized those large grey eyes. “Tessa?” he called uncertainly. The man’s attention focused Alec and he quirked an eyebrow at him, “Tessa, my darling, do you have paramours in every dimension?” He looked him up and down taking in his eye and hair color,  smirking all the while, “And my love, you do seem to have a type.” At that a groan was heard from behind them and a man with brown hair and an angular face was putting his head in his hands, “Dear God, not another Herondale. I can’t take another one.”

 

**Part 3**

Tessa stuck her tongue out at Will, in a very ladylike manner of course, before punching him lightheartedly in the arm. “Perhaps I do William but I did choose you in the end.” He grinned at her, nothing, not even the chaos of their current situation seemed to dampen his spirit. “Darling, I care not how many paramours you have, just so long as I am your favorite.” He winked at her. She finally lifted her gaze the unknown man who had addressed her by her Christian name.

“Do I know you, sir? I don’t believe we have met before?” she asked, unsure of how she could have possibly known him. He looked back at her, confused. “Of course we have, we all know you,” he gestured to the oddly dressed ladies and gentlemen beside him. 

It was Charlotte who realized it all before they did. “They must know your current self Tessa, the one existing in this time. You are a warlock after all, so it would make sense.” Tessa frowned at the thought. Yes it would make sense, but the idea of living after Will, Charlotte, and all the others whom she loved was always an upsetting one, one she hardly let herself contemplate. 

“The one existing in this time?” The golden haired man had a baffled look on his face. “If you guys aren’t from this time, when are you from?”

Cecily raised her head petulantly, “First of all you boorish dolt, not all of us are “guys.” There are a few ladies present as well, where are your manners? And of course we’re not from this time, we are dressed appropriately.” She made a point at looking up and down the two women across the room with their tight fitting clothes. Tessa couldn’t imagine having that much of her body on display, but she knew Cecily and had a feeling she was speaking partly in envy. She was always complaining about the unnecessary clothing women were made to wear, she grabbed onto any excuse to change into gear. What she didn’t think Cecily noticed was the haughty way in which the raven haired woman held her head, she had every bit of the air of self importance Cecily herself possessed. 

“We’ve traveled from London, the height of civilization and elegance, and the year 1880.” Cecily seemed to sniff a bit at the end of her declaration, indicating she thought New York to be the exact opposite of her description. 

“Toto you are soo not in Kansas anymore,” said the spectacled man while shaking his head. The dark haired woman, whom Tessa couldn’t help but call her “Cecily in trousers” in her mind, shot him a cross between a glare and confused expression. “Seriously??” He demanded, “We just watched that movie last week! Izzy, how are you ever going to catch up on mundane pop culture if you don’t pay attention??” She shrugged noncommitally at him. 

“I can’t keep living in a world where no one gets my references Isabelle Lightwood, I refuse to. I’m much too good at coming up with the best quotes to fit the moment and that kind of talent needs an audience.” This time it was his turn to glare at her while muttering something about “impossible shadowhunters.” Tessa didn’t understand anything about their exchange except that, she knew just how difficult shadowhunters could be.  

Gabriel perked up, “Lightwood? Did you say Lightwood?” He looked from “Cecily in trousers” to the man with the glasses. She raised her chin at him in challenge, much like  _ his _ Cecily did, “So? You have a problem with Lightwoods? Sorry if our family is so amazing they might’ve outshone yours and took all the glory, but can you really blame us? Sounds more like a personal problem to me.” She stared Gabriel down, daring him to deny her statement. 

Will made a disgusted noise in the back of his throat, “Ugh, Lightworms. They don’t seem to have changed much.” Tessa elbowed him to keep quiet. Gabriel shouldered roughly past them and held out his hand to the woman, “I’m Gabriel, Gabriel Lightwood.” 

“Gabriel Lightwood, the hero?” she asked. Will almost choked on the air he was breathing when he heard that. “Hero? HERO?!?” He yelled before he burst out into uncontrollable laughter. “It’s...just….like…..the Lightworms….to glorify….the biggest...worm….of...them…..all,” he managed to gasp in between bouts of giggles. Gabriel and “Cecily in trousers” both gave Will identical looks of disdain. There was certainly no mistaking the resemblance now. She turned her nose up at him and took Gabriel’s hand, “My name is Isabelle,” and then she took it upon herself to introduce the rest of her comrades. “Well this is strange, it’s not everyday you meet your great...great...great...?....grandfather,” she remarked.

After Will regained his composure, albeit still wiping tears from his eyes, he strode over to Alec and clapped him on the shoulder. “And you must be this generation’s Herondale! Yes, I see the devilishly handsome resemblance,” he declared with a wink. Alec in turn looked uncomfortable, “Um, I’m actually a Lightwood as well.  _ He’s _ the Herondale.” He gestured to Jace, whose golden hair seemed to match his skin. Will looked incredulously back and forth between them. “But he looks  _ nothing  _ like me! You’re telling me my charming good looks get lost among the generations?? How can this be? The horror!” He hysterically threw himself into Tessa, where she was actually waiting with her arms outstretched. One was always prepared for dramatic flinging about when married to a Herondale.

He brightened suddenly and Tessa recognized the maniacal glint in his eye, he always got it when he tortured his brother-in-law. Gabriel had caught the jist of the conversation and had come over to meet Alec. Will sidled over to him and smirked, “For the first time you’ve seemed to run into a bit of luck Lightworm, your descendants look like  _ me _ . You’re welcome. If this isn’t proof the universe is on my side I don’t know what is.”

Gabriel rolled his eyes in response, "Actually he looks like your sister. At least my descendant looks like my wife and has MY surname, yours has no resemblance to either you or Tessa.” Alec and Jace exchanged a look, a look Tessa recognized all too well. One that spoke volumes with no words, that people only shared if they were bonded, a look she had seen two other boys exchange all the time. With a devilish grin, Tessa remarked “So, you two are parabatai? It’s so nice to see the future generations getting along and behaving better than their forefathers.” At this both Will and Gabriel stopped talking and turned to stare at the heirs to their lines. 

“What?!  _ My  _ heir, parabatai to a Lightworm??” He turned to Tessa and wailed in despair, “Tess, this Herondale...He’s broken!” and launched himself into her arms yet again. Tessa caught him and patted him sympathetically on the head, all the while grinning at the group over his shoulder. 


End file.
